Planting implements are used for planting seeds in agricultural fields. One type, the seed drill, used for many crops including grain of small seed size, deposits seeds in a substantially continuous stream. A second type, the seed planter, used for larger plants such as corn which often have larger seeds, meters and places seeds individually, spaced apart within the row to avoid over crowding of the plants. Planting implements produced by Case Corporation, the assignee of this invention, plant up to 60 rows simultaneously in a 60 foot wide swath, and may additionally and concurrently apply other products such as fertilizers, herbicides, insecticides, and pH buffers.
Herbicides and insecticides are used in smaller quantities and are dispensed from individual bins provided for each row of crop, but seed and fertilizer, which are used in larger quantities, are stored in one or more larger central hoppers or tanks and must be conveyed from the hopper or tank to each row, distributed equally among the rows, and metered for proper application rate. Several larger hoppers are often mounted upon an implement, or a still larger hopper is provided its own wheels and is towed behind the planter or seed drill. While liquid products may be pumped to each row unit and metered for equal distribution among the row units with ease by those familiar with the art, granular products are less easily conveyed and metered. One solution to this problem has been the entraining of dry product in a stream of low-pressure air to convey the product through a duct or hose, and the utilization of manifolds to equally distribute the product among the row units. Low-pressure air is also used in the metering of seeds in planters, as well as in propelling the seeds through lengths of tube to the seed bed. Different air pressures are often necessary in different parts of a system for proper performance of the planting operation, and these pressures must be regulated by adjustment of fan speeds, damper positions, and the like.
Seed application rates, in terms of, for example, seeds per lineal foot traversed, are adjustable by the operator for different crops and growing conditions. A desired application rate having been established by the operator and the implement adjusted to that rate, it is highly desirable for the implement to steadily continue applying at that rate. If too much seed is applied, expensive seed will have been wasted, excessive down time will be incurred reloading the bins more often than should have been necessary, and plants will be crowded together too closely. If too little seed is applied, a smaller harvest than anticipated will be realized. Similarly deleterious results can occur if other product is not applied at the expected rates; too much of any product may damage or kill the seed or seedlings, while too little may leave the plants undernourished or unprotected.
Various styles and sizes of feed rolls, drums, and similar devices are available for different sizes, types, and shapes of seed and other product. They are selected by the operator and replaced as needed for changes in product being applied, usually with a relatively high degree of certainty that a proper selection has been made. Air pressure adjustment is frequently less certain, however, and is often performed by changing speed of a fan or blower from outside the implement with the tractor and implement stopped. Several iterations of stopping to check seed bed for proper application rate and consequent readjustment of fan speed may be necessary to achieve best performance, particularly if more than one product is being applied concurrently and more than one pressure must be adjusted.
Making such adjustments using iterative trial-and-error technique is a time consuming and sometimes aggravating endeavor. In some devices, such as spring-and-diaphragm pressure reducing or regulating valves, the adjustments may then at least remain undisturbed in spite of external influences such as temperature, or other weather, changes between, for example, early morning and noon, or such as high levels of vibration sometimes encountered in agricultural field operations. In other instances, droop may occur in a regulator due to a large change in load. In any such situation, a readjustment of an operating parameter may be needed or would at least be beneficial, but the need may go unnoticed due to other demands upon the operator's attention or may be thought not worth the cost or inconvenience of the one or more stops needed to make the adjustment.
An open loop control system for regulated parameters, with a real time display of actual measured values of those parameters, would make even iterative adjustments quickly and easily performed from the cab of a tractor or other vehicle while remaining in motion and in operation. A closed loop control system would further obviate the need for the system operator to frequently monitor those values and make adjustments, and would essentially perform that task for the operator and thereby free him to more closely attend to progress of the field operation itself.
One device is currently commercially available for the monitoring and control of multiple implement air velocities by adjustment of a single fan speed and of multiple branch circuit air valve settings from the cab of a tractor while the tractor and implement are in operative motion. It would be desirable, however, if additional parameters, including multiple bin pressures, could be monitored and adjusted, as well as recorded in a printout or a memory device, while the implement and tractor were in normal operative motion. It would also be desirable to be able to monitor and control bin pressures directly in units of pressure, rather than only indirectly in units of fan speed or air velocity. It would additionally be desirable to be able to monitor lubricating oil pressure of an engine or engines on the implement if the implement is so equipped. It would further be desirable to monitor and control depth or force of engagement with the soil of the seed bed ground opening tool.
It would still further be desirable, for maximum efficiency and productivity of the farming operation, to be able to variably control the ground opening tool depth or force of soil penetration using site-specific penetration depth or force set points stored in a memory device. The memory device may be programmed with a precision farming Geographic Information System (GIS) map layer or data base, and Global Positioning System (GPS) and Differential Global Positioning System (DGPS) technology and equipment could be used to accurately locate the tractor and implement with respect to the GIS locational coordinates.
Regulated parameters in an agricultural implement have heretofore been adjusted to constant values and left unchanged throughout the performance of an operation through an entire field or set of fields. However, the relatively recent inception and rapid development of site-specific precision farming techniques now make some such parameters, such as planter ground opening depth and force, operational variables which can be readily programmed and controlled on the fly.